Catechism of the Catholic Church

Lay people also fulfill their prophetic mission by evangelization, "that is, the proclamation of Christ by word and the testimony of life." For lay people, "this evangelization... acquires a specific property and peculiar efficacy because it is accomplished in the ordinary circumstances of the world." (2044, 2472) > This witness of life, however, is not the sole element in the apostolate; the true apostle is on the lookout for occasions of announcing Christ by word, either to unbelievers... or to the faithful.